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Old 22nd April 2005, 12:46 AM   #1
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Default super symmetry and balance

Mr Pass 2nd and 3rd harmonic distortion is a form of noise,unwanted frequencies that contaminate the audio spectrum ,yet you seem to prefer the 3rd over the 2nd, is there a particular reason for doing so, i ask this ina purely philotechnical context, do the 2nd harmonic circuit topologies always give higher harmonic content than the 3rd ones, they do dont they, i therefore have concluded relatively that symmetry and balance offer less harmonic content, now i ask you a purely philosophical question, i take two similar class-b monoblock amps and bridge them to form a balanced topology, would that give better harmonic performance than just using a single monoblock on its own
here is my super-symmetry and balance
any comments would be highly appreciated
Fanatic-Member Mastertech
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Old 22nd April 2005, 02:02 AM   #2
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I have good eyesight, insight, hindsight, and foresight, and furthermore being the seventh son of a seventh son, born under a caul, I am in the way of knowing that there was a question hidden in there...somewhere...
Assuming that by 'higher harmonic content' you mean higher distortion, the answer is maybe. It depends on the rest of the circuit. You cannot blindly assume that a circuit exhibiting primarily second harmonic distortion will have higher overall distortion than a circuit that has mostly third. Or vice versa.
As to whether second or third harmonic is preferable, the answer is again maybe. You seem to be seeking an absolute answer to a relative question. That's a recipe for angst and frustration.
If you're going to try to "X" an opamp circuit, you might do well to check Nelson's threads on X chip circuits. There are several of them.
Can you improve two class-B amps by creating a bridged circuit? Maybe. It depends on your criteria. Be sure that you have sufficient bias to power the load, though.

Grey
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Old 22nd April 2005, 09:24 PM   #3
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Default Re: super symmetry and balance

Quote:
Originally posted by mastertech
...a purely philosophical question, i take two similar class-b monoblock amps and bridge them to form a balanced topology, would that give better harmonic performance than just using a single monoblock on its own
If you bridge amplifiers or operate two output stages as a
single balanced one, you tend to get cancellation of 2nd harmonic
and addition of 3rd. At higher harmonics, it quickly becomes
unpredictable.

If you bridge two output stages with 3rd harmonic character
(standard push-pull, for example) the bridging usually reinforces
the 3rd harmonic. If you operate two single ended stages
balanced, you can get a lot of cancellation of their 2nd harmonic,
and the result is generally 3rd harmonic.

So, if I am planning on hearing 3rd harmonic, my favorite method
is to balance two single-ended Class A stages.

2nd Harmonic or 3rd - they are different, but I have no problem
with either.



3 paragraphs in a row starting with If.....
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Old 23rd April 2005, 06:50 PM   #4
acaudio is offline acaudio  Germany
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Default Re: super symmetry and balance

Quote:
Originally posted by mastertech
...here is my super-symmetry and balance
any comments would be highly appreciated
Fanatic-Member Mastertech
Nice,
I like your self representation
Senior Member, Design Expert

Adam
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Old 23rd April 2005, 07:29 PM   #5
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Default Re: super symmetry and balance

Quote:
Originally posted by mastertech
here is my super-symmetry and balance
To the extent implied by the trademark "SuperSymmetric",
your circuit does not fit that description as it does not have
a cross-conducted error cancellling mechanism. That's not to
say it wouldn't sound good - that would be in the details...

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Old 23rd April 2005, 11:29 PM   #6
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acaudio it is an honor to have a German Engineer comment on my Design as i know for one the high state of art of your Engineering,nice is what i say when
i see a German Design too
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Old 23rd April 2005, 11:47 PM   #7
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To the extent implied by the trademark "SuperSymmetric",
your circuit does not fit that description as it does not have
a cross-conducted error cancellling mechanism. That's not to
say it wouldn't sound good - that would be in the details...
----------------------------------------------------------------------------
Mr Pass what an honor to have posted again, ive never forgoten the splendid
american texts and your articles ive read over the years, what is a cross-conducted error cancelling mechanism, with all due respect i have also designed
other circuit topologies with acronims of the like
HSS -high super symmetric
VHSS - very high super symmetric
UHSS -ultra high super symmetric
etc...these incorporate bigger things as you can imagine
Mr Pass are you going to post any new zen or other articles at your diy site
i enjoy them like coca-cola which i drink when i design
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Old 24th April 2005, 12:52 AM   #8
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Of course it's better to ELIMINATE distortions rather than emphasize any.

Euphonic emphasis is about as desirable as eugenics!
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